The golden age of extreme gravitational astrophysics has just begun with the gravitational wave observations of merging compact binaries and time-resolved X-ray observations of rotating neutron stars. These observations carry signatures of the behavior of gravity in a regime in which this interaction is simultaneously strong, non-linear and dynamical. The search for deviations from Einstein's theory of general relativity in this uncharted extreme gravity regime had not been possible until now. In this talk, I will describe a few astrophysical signatures of dynamical Chern-Simons gravity, a classical extension of Einstein's theory that is well-motivated from string theory, loop quantum gravity and effective theories of inflation. I will show how this theory introduces a dynamical pseudo scalar that couples to the curvature of spacetime in a parity-violating way, thus avoiding solar system and binary pulsar constraints, while introducing signatures in the extreme gravity regime.